1. Field of the Invention
The subject matter disclosed generally relates to disk media of hard disk drives.
2. Background Information
Hard disk drives contain a plurality of heads that are magnetically coupled to rotating disks. The heads write and read information by magnetizing and sensing the magnetic fields of the disk surfaces.
There are generally two different types of magnetic heads, horizontal recording heads and perpendicular recording heads (“PMR heads”). Horizontal recording heads magnetize the disk in a direction that is essentially parallel with the outer surface of the disk. PMR heads magnetize the disk in a direction essentially perpendicular to the outer surface of the disk. PMR heads are preferred because perpendicular recording allows for higher bit densities and corresponding increases in the data capacity of the drive.
The areal density of perpendicular recording is limited by magnetic cross-talk between adjacent areas of the disks. One approach to limiting cross-talk is to create a disk composed of a plurality of magnetic dots that are separated by grooves. The grooves inhibit magnetic cross-talk between the magnetic dots. Such disks are commonly referred to as bit patterned media. The grooves create exposed areas of the magnetic material that can oxidize and create undesirable corrosion.